1. Field of the Invention
The present invention relates to a wireless LAN system, a host apparatus and a wireless LAN base station, and more particularly, to a wireless LAN system in which wireless terminals and base stations are connected by wireless LANs, a host apparatus which controls call origination of the wireless terminals through the wireless LAN base stations, and the wireless LAN base station.
2. Description of the Related Art
From the first, wired LANs (Local Area Networks) have been developed and used. Recent days, however, wireless LANs in each of which at least parts of a wired network are replaced by wireless lines are developed and used because the speed of the wireless lines is increased and mobile computing technology and mobile terminals have been developed.
In the wireless LAN, improvement of QoS (Quality of Service) is an important theme in order to realize the wide bandwidth and short delay time which are necessary for users and applications. Responding to this, there is proposed a system in which a wireless LAN base station determines priority in accordance with the type of data, and it sends data in order of the priority. For example, audio and motion picture data which need to be transmitted in real time are assigned higher priority than the other data, whereby it is possible that the audio and motion picture data are transmitted in a constant speed even if the amount of the other transmission data varies.
In conventional wireless LAN systems, service sets each of which comprises a wireless LAN base station and wireless terminals connected thereto are provided individually, and QoS of the wireless LAN is determined for each of the service sets.
In conventional wireless LAN systems, however, there is disadvantage that QoS is not assured when vast data of the same priority are sent to a single wireless base station because the data of the same priority are sent evenly and the transmission speed is decreased to be a bottleneck.
In addition, there is another disadvantage that QoS is not assured because the priority of data is determined for each of the service sets and the priorities of data transmitted via a plurality of wireless LAN base stations may differ between wireless LAN base stations.
In such condition, a roaming from a wireless LAN base station to another wireless LAN base station is conducted and transmission connection is switched, the priority of data changes, and therefore, QoS in the transmission line is not assured.